1. Technical Field
The present invention relates to an image forming apparatus employing an electrophotographic method, such as a copier, a printer, a facsimile machine, and a multifunction apparatus having one or more capabilities of the above devices.
2. Related Art
In an image forming apparatus employing an electrophotographic method, such as a copier, a printer, a facsimile machine, and a multifunction apparatus having one or more capabilities of the above devices, an electrostatic latent image formed on a photoreceptor or a photoreceptor drum as an image carrier is supplied with toner by a developing means to render the latent image visible and the thus-formed visible image is transferred to a recording medium, for example, a sheet of paper.
A processor part of the image forming apparatus is divided into two parts due to a difference in lifetime: one is a process cartridge including a developing means and used as a developer receiving cartridge; and another is a toner cartridge to supply toner as a developer replenishing cartridge. The toner cartridge includes a toner outlet serving as an opening through which the developer is discharged. The process cartridge includes a toner intake port serving as an opening through which the developer is taken in. The toner outlet and the toner intake port are communicated with each other so that the process cartridge is replenished with toner.
Thus, because the parts with a different lifetime are separately formed, consumable parts may be replaced effectively. However, because the process cartridge and the toner cartridge are separately formed and therefore are positioned separately, a problem of scattering of toner occurs.
To cope with this problem, JP-2001-222160-A discloses a technique in which a shutter mechanism is disposed between the process cartridge and the toner cartridge. The process cartridge includes a toner intake port shutter disposed at the toner intake port and the toner cartridge includes a toner outlet shutter disposed at the toner outlet. The toner intake port shutter of the process cartridge opens the intake port when the process cartridge is mounted to the image forming apparatus and closes the intake port when the process cartridge is removed from the image forming apparatus. As to the toner outlet shutter disposed at the toner outlet of the toner cartridge, the toner outlet shutter opens the outlet when the toner cartridge is mounted to the image forming apparatus and closes the outlet when the toner cartridge is removed from the image forming apparatus.
The same JP-2001-222160-A describes that the disposition of a seal member for preventing the toner from scattering is recommended. Specifically, the seal member formed of urethane foam or felt is sandwiched between the intake port shutter and an intake port shutter cover or between the outlet shutter and an outlet shutter support member, for example.
However, the seal member of JP-2001-222160-A does not include a pressing means to press the toner cartridge, and therefore, when the toner cartridge is installed, the toner cartridge may float at a joint portion with the process cartridge due to the seal member disposed for preventing the toner from scattering or due to a resistance from the shutter mechanism. In such a case, when the external cover is closed without the joint portion being appropriately sealed, there occurs a problem that parts or components are damaged or that the toner scatters.